C Library Avro Record Fields Question

["Gill, John" <Jo...@Teradata.com>]

Hello,
I am looking at using the Avro C Library API for a project and was wondering why Record Fields are not first class "objects"? Meaning, there is not an AVRO_FIELD type for them. Looking at the python and Java implementations there is a Field Class in both languages that can be accessed and utilized. However, in the C implementation there is an avro_schema_field_t but the index and name attributes are sort of useless (except for hashing) and the type is always returned. Additionally, all the interfaces for accessing a field are done via avro_schema_record_field_*.

I was looking to try and add some default value support for the project I am working on but am finding that without the ability to return an AVRO_FIELD type that the interfaces get ugly very quickly.

    avro_value_t avro_schema_record_field_get_default_by_index(rSchema, i);
    avro_value_t avro_schema_record_field_get_default_by_name(rSchema, "field1");
    int avro_schema_record_field_set_default_by_index(rSchema, i, value);
    int avro_schema_record_field_set_default_by_name(rSchema, "field1", value);

Additionally, if we wanted to add any other attributes from the Specification ("doc", "order", "aliases") then the same very long API call names persist.

    char * avro_schema_record_field_get_doc_by_index(rSchema, i);
    char * avro_schema_record_field_get_doc_by_name(rSchema, "field1");
    int avro_schema_record_field_set_doc_by_index(rSchema, i, value);
    int avro_schema_record_field_set_doc_by_name(rSchema, "field1", value);

The reason I ask, and it's problematic, is because such a change would break existing API functionality. Currently a call to avro_schema_record_field_get returns the type attribute of an avro_record_field_t. With the proposed change the new avro_record_field_t would look like:

    struct avro_record_field_t {
        struct avro_obj_t obj;
        int index;
        char *name;
        avro_schema_t type;
    }
Thus, the obj attribute would be returned and a new set of API functions would be used to access information about a record field:

    int avro_schema_field_get_index(fScehma);
    char * avro_schema_field_get_name(fSchema);
    avro_schema_t avro_schema_field_get_type(fSchema);
    avro_value_t avro_schema_field_get_default(fSchema);
    char * avro_schema_field_get_doc(fSchema);

Interested in thoughts about the change and possibly why it was designed this way. Looking at C++ it seems to have the same issue.

Thanks,
- John